1. Field
The present invention relates to computers and computer networks. More particularly, the present invention relates to network traffic classification method.
2. Description of Related Art
Over the past few years, the Internet infrastructure has become a critical part of the global communications fabric. Emergence of new applications and protocols, such as voice over Internet Protocol (VoIP), pear-to-pear (P2P), and video conference increase the complexity of Internet. Accompanied with this trend is the increasing demand on more reliable and secure service. As a result, quality of service (QoS) becomes a more and more important issue. For example, transmission of real-time voice and video traffic has high bandwidth, low delay, and low packet loss rate requirements. Current best-effort Internet does not provide direct QoS guarantee to these real-time applications. At the same time, enterprise network administrators may want to restrict network bandwidth used by unauthorized VoIP or P2P applications. Hence, ability to guarantee or limit the QoS of specific types of network traffic may be desired in various different scenarios. Differentiated Services (DiffServ) is a method designed to guarantee different levels of QoS for different types of network traffic. It is achieved by configuring a “type of service” (TOS) field in a network data packet. For example, the DiffServ code point (DSCP) field in the IP header may be set according to the type of the network traffic for it to receive appropriate level of priority. Unfortunately, such design depends highly on network protocols, especially proprietary protocols, for observing DiffServ regulations. For example, in the worst case, the DiffServe method may be defeated if multiple protocols all set DSCP of their corresponding data packets to the highest number. Therefore, there is a need to classify network traffic flows in real time instead of relying on any tags in packet headers.